Gap in slider bars

I have an ArcGIS javascript 3.20 application that uses slider bars (both opacity and time) . All of the slider bars are drawn with a gap and the indicator is positioned at the end of the gap. Can anyone explain this behaviour?

Hmm.. As I said I do not see that issue. It is possible that you have a css rule that has low specificity and being applied to the slider unintentionally. Using your browsers dev tools you can inspect the slider to see if some errant padding is being applied by some css rule.